[Ifeffit] Hephaestus edge step calculation

[Bruce Ravel]

Guanghui,

Thanks for the helpful bug report.  Turns out to be a silly typo.
It's fixed at the head of the github repository and will be in the
next windows installer.

If you cannot wait, it is a trivial fix.  See:

 
https://github.com/bruceravel/demeter/blob/master/lib/Demeter/UI/Hephaestus/Formulas.pm#L176

On your computer, you can replace the file

   C:\strawberry\perl\site\lib\Demeter\UI\Hephaestus\Formulas.pm

or edit it to change line 176, which says

   $density *= $parent->{density};

to

   $density *= $parent->{density}->GetValue;


Cheers,
B



On 06/18/2015 03:01 PM, Guanghui Zhang wrote:
> Hello, Bruce.
> Thanks very much for writing and keeping upgrading the amazing software.
> I was mainly doing homogeneous catalysis, so most of my samples were
> solution samples. I found that it was quite convienent to calculate the
> absoption length and edge step using the old version Hephaestus (ifeffit
> 1.2.11). Simply go to the Formulas tab, choose Molarity, type in the
> formula, molarity, and energy. The calculation results will show up
> after clicking the Compute button. For example, if I type in the Formula
> as Pt, molarity as 0.03 mol/L and Energy as 11564 eV (Pt L3 edge), the
> calculation results showed as follows:
> element   number   barns/atom cm^2/gm
>   --------- ----------------------------------
> Pt       1.000 63044.107      194.641
> This weighs 195.090 amu.
> Absorbtion length = 0.878 cm at 11564.00 eV
> for a 0.03 molar sample.
> Unit edge step length at Pt L3 edge (11564.0 eV)
> is 15108.1 microns
>
> Remember that a molarity calculation only
> considers the absorption of the solute.
> The solvent also absorbs.
> The Elam database and the total cross-sections
> were used in the calculation.
> However, in the new version Hephaestus (Demeter 0.9.22, trial version 4,
> Windows 8 64 bit). It does not work.
> If I type the same informaiton, Pt, 0.03 mol/L, 11564 eV. The following
> results showed up.
>
> element number barns/atom cm^2/gm
>
> --------- ----------------------------------
>
> Pt 1.000 63044.107 194.641
>
> This weighs 195.090 amu.
>
> Absorption length = *0.0 micron* at 11564 eV for a 0.03
>
> molar sample.
>
> Unit edge step length at Pt L3 edge (11564.0 eV) is
>
> *0.0 microns*
>
> Remember that a molarity calculation only considers
>
> the absorption of the solute. The solvent also
>
> absorbs.
>
> The Elam database and the full cross-sections were
>
> used in the calculation.
>
> If I do the calculation for the solid samples using "density" instead of
> "Molarity", the calculation worked fine.
> I am wondering if there is any problem with my softwar and/or laptop, or
> there is a missing function in the new version Hephaestus.
> Thanks
> Guanghui
> 2015-06-18
> ------------------------------------------------------------------------
>
>
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>


-- 
  Bruce Ravel  ------------------------------------ bravel at bnl.gov

  National Institute of Standards and Technology
  Synchrotron Science Group at NSLS-II
  Building 535A
  Upton NY, 11973

  Homepage:    http://bruceravel.github.io/home/
  Software:    https://github.com/bruceravel
  Demeter:     http://bruceravel.github.io/demeter/